The present invention relates to a method of removing off-flavor from foods such as seafood, meat products and vegetables, a deodorizer, and the like.
Among the factors undesirably influencing the quality of food are so-called off-flavors, e.g., the fishy smell of seafood, the fleshy smell of meat, and the grassy smell of soybean. It is known to use sake, wine, shochu, mirin (a sweet sake used as seasoning), etc. in processing or cooking food for the purpose of masking such off-flavors. The deodorizing effect of such substances is considered to be mostly attributable to ethanol.
In addition to ethanol mentioned above, the following substances are known to be effective for deodorization: amino acids and organic acids [J. Jap. Soc. for Food Science and Technology, 29(6), 340 (1982)], amino-carbonyl reaction products [J. Fish Sausage, 212, 15 (1982)], saccharides [J. Jap. Soc. for Food Science and Technology, 46(5), 319 (1999)] and phenol compounds [J. Jap. Soc. for Food Science and Technology, 29(7), 426 (1982)].
Smoking is known as one of the conventional methods of deodorization utilizing food processing techniques. It is reported that the above-mentioned phenol compounds are concerned in the deodorization by smoking [Bull. of the Jap. Soc. of Scientific Fisheries, 47(1), 113(1981); J. Fish Sausage, 212, 15 (1982)].
Vanillin, which is a kind of phenol compound, is well known as a substance that overcomes the odor of trimethylamine, off-flavor in seafood. However, the characteristic sweet smell of vanillin is regarded as an undesirable odor in certain kinds of foods and thus prevents the utilization of vanillin as a deodorizer.
4-Vinylguaiacol, which is a kind of phenol compound, is a precursor of vanillin. In the field of brewing of sake, wine, etc., 4-vinylguaiacol itself is considered to be one of the off-flavor components, and studies are made to minimize its formation in the process for producing such brewage.
On the other hand, certain yeast and mold are known as enzyme source of ferulic acid decarboxylase having the activity to form 4-vinylguaiacol from ferulic acid, and the ferulic acid decarboxylase gene of yeast has been obtained [Gene, 142, 107 (1994); Japanese Published Unexamined Patent Application No. 276788/98].